Thank you. My husband looked at this pic and climbed up there, disconnected a few things, taped the mains together and connected the loop. All working properly now. He just needs to go out and get a proper cap to cover the end of the mains. He is looking for one of them now. Thank you again!!!! I no longer need to be blinded on my trips to the bathroom in the middle of the night.

My husband is telling me that it is a "loop" wire.

"It has a neutral, a common, an earth and a loop wire."

He has just gotten home, and I bombarded him with this thread. No pics just yet for you.

That looks pretty similar. Thank you for your suggestion, I will update once the husband returns.

It's on its own switch. It is in the bathroom, the other lights that have been replaced so far are in the loungeroom and 2 of the bedrooms. Only the bathroom one is not turning off. When the old light fixture was in, it worked normally. I will ask my husband to get some pics when he gets home. I'll see if he minds pulling the light down again so we can get some pics of all the wires that are in the roof and going into the light (not sure if that's what you mean by "Junction box").